Material responsive switch actuator



' Jan. 17, 1950 T, L, LANE 2,494,819

MATERIAL RESPONSIVE SWITCH ACTUATOR 2 Sheets-Sheet 1 Filed Sept. 26,1947 INL'EIIIIH T/zomasLlLane Jan. 17, 1950 T. L. LANE MATERIALRESPONSIVE SWITCH ACTUATOR ZSheets-Sheet 2 Filed Sept. 26, 1947 WVIRI \Nlm'eutm Thomas L.Lane

A tto rneyx Patented Jan. 17, 1950 MATERIAL RE SPONSIVE SWITCH ACTUATORThomas L. Lane, Three Forks, Mont. Application September 26, 1947,Serial No. 776,228

2 Claims.

This invention relates to an actuating switch for hoppers, feed boxes orother similar containers and more particularly to a, switch actuatingmechanism contained therein and actuated by the contents of the hopperor feed box for closing or interrupting an electric circuit.

More particularly, an object of the presentinve'ntion is to provide aswitch actuator of extremely simple construction which is capable ofbeing readily mounted in feed boxes or hoppers and which is providedwith means for supporting a conventional mercury switch which may beinterposed in any suitable electric circuit and whereby the switch willbe rocked in unison with a part of the actuating mechanism forcompleting the circuit in one position thereof or for interrupting thecircuit in another position of said mercury switch.

Various other objects and advantages of the invention will hereinafterbecome more fully apparent from the following description of thedrawings, illustrating a preferred embodiment and application thereof,and wherein:

Figure 1 is a top plan view, partly in section showing the switchactuator disposed in a feed box or hopper of a stoker;

Figure 2 is a longitudinal, substantially central sectional view, partlyin side elevation thereof;

Figure 3 is an enlarged substantially central longitudinal sectionalview showing the parts in a different position than that assumed inFigure 2;

Figure 4 is a cross sectional view of the switch actuating mechanismtaken substantially along a plane as indicated by the line 4-4 of Figure3, and

Figure 5 is a substantially horizontal sectional view taken along aplane as indicated by the line 5-5 of Figure 3.

Referring more specifically to the drawings, for the purpose ofillustrating a preferred application and use of the switch actuator,designated generally 6 and comprising the invention, a portion of a feedbox or hopper is shown at 1 containing coal or other material 8 which isfed outwardly through the bottom thereof, not shown, by gravity into astoker conduit, not shown. In employing the feed box or hopper forsupplying coal to a furnace stoker, it is desirable to maintain aquantity of the coal in the feed box or hopper at all times so as tofunction as a smoke and combustion gas seal to prevent the smoke andcombustion gases, escaping through the stoker conduit and feed box orhopper into the room or enclosure in which said hopper or feed box islocated.

Accordingly, it is the primary object of the present invention toprovide an actuator mechanism for a switch that is normally maintainedin a position for closing a circuit of an electric drive means, notshown, for actuating a stoker screw or other feed mechanism, by the coalor other material in the feed box or hopper and which, when said coalfalls below a predetermined level so that further operation of thestoker would break the gas and smoke seal by emptying the feed box, theactuating mechanism will move to a position for interrupting theelectric circuit for stopping operation of the Stoker.

The switch actuator, designated generally 6 and comprising the inventionincludes a housing, designated generally 9 which is disposed within thefeed box or hopper and which is suitably secured to one side or end Wallthereof. The housing 9 includes a bottom or base lil which is fixedlypositioned with respect to the hopper I and a cover I l of substantiallyinverted V-shaped cross section, as best seen in Figure 4, which isprovided with outturned flanges 12 at the bottom thereof which rest uponthe housing bottom ID adjacent the side edges thereof and which aredetachably secured thereto by fastenings l3. The cover II at its large,rear end is provided with an outturned flange M on each side thereofwhich is detachably secured to the aforementioned side or end wall ofthe hopper or feed box 'i by additional fastenings Ill.

The inner end it of the housing 9 is open and the inner end of the coverII and bottom [0, defining said opening IB, are provided with outturnedflange portions I! over which is stretched and detachably secured theenlarged end of a boot it which is formed of a flexible material andpreferably of a material which is also re,- silient, such as rubber. Theboot l8 has a restricted opening IS in the opposite end thereof.

The housing 9 is provided with an upstanding post 20 which is detachablysecured by a threaded extension 2! and nut 22 to the bottom I0,intermediate of its ends and substantially intermediate of its sideedges. The upper portion of the post 20 is longitudinally slotted asseen at 23 and with said slot opening in a direction longitudinally ofthe housing 9. Another shorter post 24 is likewise provided with alongitudinal slot 25 in its upper end which aligns with the slot 23. Astill shorter post 26 is similarly secured detachably to the bottom l0and between the open end l6 of the housing and the post 24 and also hasthe slotted upper end 21, aligning with the slot 25; said posts 20, 24and 26 being disposed in longitudinal alignment, as clearly illustratedin Figure 1.

A lever 28 is pivotally supported adjacent one end thereof in the slotof post 24 by a pivot pin 29 which extends through the slotted portionthereof and the longer end of said lever 28 extends rearwardly or towardthe large end of the housing 9 and away from the open end It thereof andhas a portion extending through the slot 23 of the post 20 foroscillating movement therein, when the lever 28 rocks on its pivot 29.An expansion coiled spring 3!) is disposed loosely on the post 20 andhas its lower end resting on the housing bottom It] and its upper endbearing against a washer 3| which in turn bears against the bottom edgeof the lever 28 for urging said lever to rock in a counterclockwisedirection on its pivot 29.

The lever 28, at the end thereof remote to the pivot 29 and the housingend I6, is provided with a demountable supporting hanger or bracket 32which is detachably clamped thereto by a fastendisposed at the outer endof the bracket 32.

A lever 31' is pivotally mounted adjacent one end thereof in the slot 27of the post 26 by a pivot pin 38 which extends therethrough and theshorter end of the lever 31 is disposed substantially beneath theshorter end of the lever 28 and is connected thereto by a link 39 whichis pivotally connected at its ends to the shorter ends of said levers.The opposite, longer end of the lever 37 extends outwardly through theopen end 18 of the housing, through the boot is and outwardly throughthe open restricted end i 9 thereof which engages closely around aportion of the lever 37. The outer portion of said longer end of lever31, which is disposed outwardly of the boot l8, has attached to theupper edge thereof a platform or treadle 48 which is disposed insubstantially a horizontal plane within the feed box or hopper 1.

The spaced contacts 35 and 36 are adapted to be connected to conductorwires 4i and 42, respectively, forming a part of an electric circuit,not shown, between a source of electric current and the electrical motoror driving means, not shown, of the stoker.

When the hopper or feed box I is sufficiently filled with coal or othermaterial 8, as seen in Figure 2, the weight of said material on the ure2 and through the connection of the link 39, the lever will be caused toassume a similar position with the longer end of the lever disposed inlowered position and so that the spring is com- Dressed.

With the levers 3? and 28 thus disposed, the mercury 43 within the tubeof the mercury switch 34 will flow toward the end containing thecontacts 35 and 36 for bridging the gap therebetween for completing ormaintaining the circuit, previously referred to. Should the coal ormaterial 8 be fed from the hopper or feed box 1, without beingreplenished, sufficiently so that the level thereof falls below thelevel of the position of the treadle or platform 40 of Figure 2, theWeight on said platform will be thereby diminished sufliciently so thatthe spring 30 can react to cause the lever 34 to rock counter-clockwisefrom its position of Figure 2 to its position of Figure 3 therebycausing the lever 31 to rock clockwise from its Figure 2 to its positionof Figure 3 and which will cause the mercury switch 34 to be inclined inthe other direction so that the mercury 43 contained therein, will flowaway from the contacts 35 and 36 for interrupting the circuittherebetween thereby interrupting the circuit for operating the stokerto shut off the stoker before the coal or material 8 has been depletedfrom the feed box 1, sufficiently to break the smoke and gas sealprovided thereby. Likewise, it will be readily apparent that the circuitwill thus be maintained in an interrupted position until the coal ormaterial 8 is replenished in the feed box 1 sufficiently so that theweight thereof will cause the platform 40 to return to its position ofFigure 2 to thereby return the switch actuating parts 6 to the positionsas illustrated in Figure 2 for bridging the gap in the electric circuitprovided between the contacts 35 and 36 by the mercury 43 flowing backinto engagement with both of said contacts. Obviously, the flexible bootis will allow the lever 31 to swing freely between the positions ofFigures 2 and 3 while at the same time affording a closure to preventany of the coal or material 8 from entering the housing 9.

The actuating mechanism 6 could also be utilized for other purposes suchas regulating the supply of a material 8 to the hopper or bin 1 by anelectrically driven feeder means through the simple expedient ofreversing the position of the mercury switch in the bracket 32 so thatwhen the parts were in their positions of Figure 3 a circuit would becompleted through the mercury switch actuating the feeder means forsupplying the hopper or bin 1 but when the supply of the material 8therein rose to a certain level, as seen in Figure 2, the weight of thematerial 8 on the platform 40 would rock the parts to their positions ofFigure 2, so as to interrupt the feeder drive means circuit to preventoverflowing of the hopper or bin 7.

Various other modifications and changes are contemplated and mayobviously be resorted to, without departing from spirit or scope of theinvention as herein after defined by the appended claims.

I claim as my invention:

1. In a material responsive switch actuator, a housing mounted in acontainer, a pair of levers pivotally supported near adjacent endsthereof closing position,

' as a unit in a direction for causing the adjacent ends thereof toswing downwardly and tachably mounted therein for receiving the adjacentend portions of said levers and in which said adjacent end portions arepivotally mounted.

2. A material responsive switch actuator comprising, a housing mountedin a container, a pair of levers pivotally supported near adjacent endsthereof within said housing, a link connecting said adjacent lever endsand pivotally connected to each of the levers, one of said levers havingits opposite ends extending outwardly of the housing into the container,a platform mounted on said last mentioned lever end and adapted to beengaged by material within said container for retaining the platform andthe lever end connected thereto in a depressed position, a mercuryswitch connected to the opposite end of the othen lever for movementtherewith and disposed in a circuit closing position at one extremity ofthe swinging movement of said last mentioned lever end and in a circuitinterrupting position at the other extremity of the swinging movement ofsaid last mentioned lever end, spring means for biasing said levers as aunit in a direction for causing the adjacent ends thereof to swingdownwardly and the remote ends of the levers to swing upwardly when theweight of the material in the REFERENCES CITED The following referencesare of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,015,939 Justus Oct. 1, 1935FOREIGN PATENTS Number Country Date 329,447 Great Britain May 22, 1930

